systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system.
The key commands or arguments you will use with systemctl are the following:
list-units [PATTERN...] List loaded units
--2018-08-16 05:11:16-- https://downloads.linux.hpe.com/repo/spp/rhel/6/x86_64/current/CP017004.scexe
Resolving downloads.linux.hpe.com (downloads.linux.hpe.com)... 126.96.36.199
Connecting to downloads.linux.hpe.com (downloads.linux.hpe.com)|188.8.131.52|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1525561 (1.5........
ValueError: new value non-existent xfs filesystem is not valid as a default fs type
Pane is dead
From what I read this is misleading and has to do with the fact that the initrd and kernel are mismatched.
This is a hard situation because for some older hardware I am using the Centos Plus kernel which has modules that I require for an older server/NIC. This seems to have cropped up in the past few months and there is no simple fix........
# yum -y install qemu-kvm
Loaded plugins: fastestmirror
Setting up Install Process
Loading mirror speeds from cached hostfile
* base: mirror.lzu.edu.cn
* elrepo: ftp.utexas.edu
* epel: ftp.jaist.ac.jp
* extras: mirrors.aliyun.com
* openvz-kernel-rhel6: mirror.fdcservers.net
* openvz-utils: mirror.fdcservers.net
* updates: mirrors.nwsuaf.edu.cn
Stopping httpd: [FAILED]
Starting httpd: httpd: Syntax error on line 73 of /etc/httpd/conf/httpd.conf: Cannot load /etc/httpd/modules/mod_file_cache.so into server: /etc/httpd/modules/mod_file_cache.so: cannot open shared obje........
Say you have a bunch of files like this:
What if you want to mass rename them?
the rename tool can work just like sed
For Debian based distros:
Note "file" is what we search for and "newname" is what we replace it with, so substitute according to your requirements.
rename s/file/newname/ name-file-*.jpg
For the first two entries comment out #mirrorlist and uncomment #baseurl and then it worked
openvz yum problem Centos 6.5 cannot find file on mirror:
Loaded plugins: fastestmirror
Determining fastest mirrors
* openvz-kernel-rhel6: mirrors.ustc.edu.cn
* openvz-utils: mirrors.ustc.edu.cn
./configure: line 91: cd: /lib/modules/2.6.32-042stab084.25/build: No such file or directory
Error: kernel version not found.
Please make sure your kernel is configured.
dr-xr-xr-x. 4 root root 4096 Feb 21 06:13 ..
lrwxrwxrwx 1 root root 45 Feb 21 06:13 build -> ../../../usr/src/kernels/2.6.32-042stab084.25
drwxr-xr-x 2 root root 4096 Feb 12 20........
I flashed an LSI Logic firmware to it and it broke the BIOS (cannot do Ctrl+R) for booting purposes but allows other functionality to work normally.
I tried downgrading to a Dell firmware for Perc 6i but it won't work, not even with MegaCli
--2013-08-26 12:53:39-- http://downloads.dell.com/FOLDER00416606M/1/SAS-RAID_Firmware_W83M2_LN32_6.3.1-0003_A14.BIN
pecl install apc........
ERROR 1146 (42S02): Table ‘mysql.servers’ doesn’t exist
This happened to me on a system running Centos with the REMI repo and a new version of Mysql 5 (which the official Centos/RHEL does not support on version 5).
The solution is just to run this program "mysql_upgrade", after that flush privileges will work.
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to 192.168.1.253 [192.168.1.253] port 22.
debug1: Connection established.
debug1: permanently_set_uid: 0/0
debug1: identity file /root/.ssh/identity type -1
debug1: identity file /root/.ssh/id_rsa type 1
debug1: identity file /root/.ssh/id_d........
For whatever reason the current OpenVZ yum repo file enables the RHEL6 version of OpenVZ, why is this bad? Because if you're running Centos 5 it still defaults to using the kernel from RHEL6 which won't work on RHEL5/Centos 5.
I only realized this after wondering why I couldn't boot into OpenVZ that it was using one meant for RHEL6.
To fix the problem you have to edit /etc/yum.repos.d/openvz.repo and disable the "[openvz-kernel-rhel6]" section by changing........
ip_conntrack: table full, dropping packet.
A lot of clients I've seen have this issue, it really seems the default level is way too small. Once this connection tracking table becomes full then packets get dropped which is obviously a bad thing.
One thing to be mindful of though is that 350 bytes of memory are used per entry so there is some justification for not keeping it too high. However, if you have multiple servers running or high traffic daemons........
It really is as simple as:
cdrecord -v dev=/dev/sr0 pathtoyourisoimage.iso
-v is for verbose, I prefer it but if you don't you won't see as much output like below (I like to know the details and exactly what's happening)
dev=/dev/sr0 specifies the device name of your burner (they say not to use it and to specify some weird annoying device string but using the raw /dev has always worked for me and is how it should have been implemented from the start IMHO)........
A few days ago this happened on multiple Centos 5 servers and apparently anyone using rpmforge was affected by this error and there was no solution other than disabling that repo to fix it.
To some this highlighted a few points, that there is a reason RHEL exists with full paid support, and also that this could be a vulnerability and huge flaw with yum. A yum search or install should not segfault just because the rpmforge repo goes down.
Fortunately it came back up........
Warning: Unable to open /dev/fd0 read-write (Read-only file system). /dev/fd0 has been opened read-only.
That's a very annoying error, it's simply because Centos for some reason thinks it's wise to load the "floppy" kernel module, who has a floppy drive? I haven't seen or used a floppy for over 12 years!
It's more than just annoying, if you probe the drives attached to your system, eg. with grub or partprobe, it keeps trying to locate a flopp........
It's weird because I have a nearly identical box and setup and I can update the ovzkernel-PAE* just fine but on this box it doesn't work.
I only get this error with the openvz.repo and not others such as Centos-Base.repo
With my other server it works normally:
Setting up Update Process
--> Running transaction check
---> Package ovzkernel-PAE.i686 0:2.6.18-238.12.1.el5.0........
Virtually no system has a floppy disk drive anymore but you will often find your Linux distribution insists that you do or should have one :)
The solution is to remove the floppy module and prevent it from loading on the next reboot.
echo "blacklist floppy" >> /etc/modprobe.d/blacklist
sudo echo "blackli........
rpm -i http://download.virtualbox.org/virtualbox/3.2.8/VirtualBox-3.2-3.2.8_64453_rhel5-1.i386.rpm
error: Failed dependencies:
libGLU.so.1 is needed by VirtualBox-3.2-3.2.8_64453_rhel5-1.i386
libSDL-1.2.so.0 is needed by VirtualBox-3.2-3.2.8_64453_rhel5-1.i386
libXmu.so.6 is needed b........
I've never understood how to enable and disable services for different run levels in Debian based distros, it's just weird, annoying and doesn't make sense. I much prefer chkconfig from RHEL.
Just install the package called 'rcconf' and be done with it. rcconf makes things easy for you.
apt-get install rcconf
Reading package lists... Done
Building dependency tree
Reading state information... Done........
I wasted a lot of time wondering why I could never find those packages.
Check the /etc/yum.conf file and at the bottom look for the "exclude=" line.
Below is what I found in mine
exclude=apache* httpd* mod_* mysql* MySQL* da_* *ftp* exim* sendmail* php* bind-chroot*
Just remove those entries or uncomment that line and you'll get access to the missing applications.........
Basically the two main types of distros are Debian and RHEL/Centos based. I'm just going to give a quick overview of how the configuration of IP interfaces works in Debian/Centos based distros.
*Just one thing to remember, when setting IPs statically you have to manually specify a DNS server in /etc/resolv.conf (since DHCP is what normally does it automatically)
The IP (DHCP &........
Proxmox has made this free utility to backup running OpenVZ containers. It's a great program which is actually just a PERL script but gets the job done. This program is not 100% required because all it really does is cp -a from your container's path as far as I know but it is still good to have uniformity to how you backup your containers.
For RPM distros such as Centos/RHEL/Fedora etc.. download and install this:
It's a bit of a pain that many basic third party tools that aren't put of the main Centos/RHEL repositories are not available unless you compile them or install the RPMForge Repo.
*Updated 08/29 with new download location changed from apt.sw.be to rpmforge.sw.be
Here's a quick, simple/cut&paste way to do it:
rpm -i rpmforge........
This way should work on all Linux machines, at least RHEL/Debian (Ubuntu) based distros but most likely all and also should work on many Unix style machines I believe.
Many OS's have tools to update the timezone, but most of them (even if command line) require several bloated packages and even Xorg/KDE based packages etc..
Your time zone info file is actually in /etc/localtime if you open this file in vi/vim/pico you'll see it's gibberish (binary code or another encodin........
There's a lot of information and guides on OCFS2 for RHEL and Centos Linux but the package setup and configuration is slightly different and this has thrown some people off.
You should install the following packages to get started:
apt-get install ocfs2-tools ocfs2console
In RHEL/Centos the main configuration file is located in /etc/sysconfig/o2cb
However in Debian based Linux it is located........